Electric vehicles are about to form a widespread alternative to vehicles provided with internal combustion engines. A plug-in electric vehicle is equipped with one or more electric motors operatively connected to the driving wheels of the vehicle and a battery pack for storage of electric energy.
A rather large and heavy battery pack is needed for running a vehicle on electric energy over distances that are sufficiently long, say, more than 100-200 km, to make plug-in electric vehicles a really interesting alternative. A challenge in the development of electric vehicles is the design of such a battery pack and how to install it in the vehicle. Besides the considerable weight and dimensions of the battery pack, there are regular safety demands with regard to collision energy absorption for the vehicle, etc., and for electric vehicles there are further safety issues related to damage of the battery pack and to electric hazards (short circuits, etc.).
Battery packs for electric cars are typically arranged in the bottom of the vehicle below the floor of the passenger compartment. An advantage of such an arrangement is that it provides for a low centre of gravity for the vehicle. Various arrangements have been presented for how to design the body frame structure for such vehicles and for addressing the different safety aspects, such as avoiding puncture of the battery pack, which might lead to fires that are difficult to extinguish.
US2013/0252059 discloses an under-floor battery pack arrangement that is stated to provide dimensional stability of parts while reducing the weight using a plastic composite.
US2013/0119706 discloses a floor-mounted battery pack supported by a vehicle body frame that includes deformable shock absorbing members that, when buckling in the event of, e.g., a head-on collision, causes rigid members to be positioned in a certain manner so that short circuits/ground fault can be prevented.
Although there are a lot of designs proposed for electric vehicles that solve particular problems, there is still a need for solutions that generally improve safety for electric vehicles, simplify production, etc.